ES2305941T3 - PROCEDURE AND APPARATUS FOR COLLECTING BACTERIAL CELLS, PROCEDURE FOR ACCLIMATING BACTERIAL CELLS AND WASTEWATER TREATMENT EQUIPMENT. - Google Patents

Abstract

A method for collecting bacterial cells comprising the steps of: feeding the water to be treated containing ammonium and nitrite to a anaerobic ammonium oxidation vessel (12) to denitrify the ammonium and nitrite by anaerobic ammonium oxidizing bacteria; and feeding the denitrified treated water to an acclimatization vessel (14) provided in a path of a treated water pipeline or a feedback pipeline to the anaerobic ammonium oxidation vessel (12) to collect anaerobic ammonium oxidizing bacteria in the water treated as immobilized microorganisms attached to an immobilization material in the acclimatization vessel (14).

Description

Procedure and apparatus for collecting cells bacterial, procedure to acclimatize bacterial cells and wastewater treatment equipment.

1. Field of the invention

The present invention relates to a procedure and to an apparatus for collecting bacterial cells, in particular to a technique for collecting ammonium oxidizing bacteria anaerobes used for anaerobic oxidation of ammonium.

2. Description of the related technique

The nitrogen components contained in the sewage and industrial discharges produce eutrophication in lakes and reduce the level of dissolved oxygen in rivers and, by Therefore, they must be removed. Examples of the main components of nitrogen contained in sewage and industrial discharges include ammoniacal nitrogen, nitrite nitrogen, nitrogen Nitrate and organic nitrogen.

Conventionally, if the nitrogen in such water residual has a low concentration ion exchange and are used Oxidation by chlorine or ozone to remove nitrogen. If he nitrogen has a medium or high concentration is used Biological treatment and normally works in the following terms.

In the biological treatment, the nitrification and denitrification treatment are performed by aerobic nitrification and anaerobic denitrification. In aerobic nitrification, ammoniacal nitrogen and nitrite nitrogen are oxidized by ammonia oxidizing bacteria ( Nitrosomonas, Nitrosococcus , Nitrosopira, Nitrosolobus , etc.) and nitrite oxidizing bacteria ( Nitrobactor, Nitrospine, Nitrococcus, Nitrospira , etc). On the other hand, in anaerobic denitrification, denitrification is performed by heterotrophic bacteria ( Pseudomonas denitrificans , etc.).

A nitrification vessel for Aerobic nitrification works at a load of 0.2 to 0.3 kg-N / m 3 / day and a container of denitrification for anaerobic denitrification works at a 0.2 to 0.4 kg-N / m3 / day load. To treat the nitrogen contained in a total concentration of 30 to 40 mg / l in sewage, sewage must be contained in a container of nitrification for 6 to 8 hours and in a container of denitrification for 5 to 8 hours and containers of Large scale treatment In addition, a nitrification vessel and a denitrification vessel is designed to work at the loads described above for spills industrials that only contain inorganic substances. But nevertheless, denitrification of such wastewater requires substances organic and therefore methanol is added at a concentration of three  four times that of nitrogen. For this reason it is not only required an initial expense, but also a great operating expense.

In this situation it has recently attracted the attention a procedure to remove nitrogen comprising the anaerobic ammonium oxidation (for example, application publication Japanese Patent No. 2001-37467 and publication of Japanese patent application No. 2003-24990). This anaerobic ammonium oxidation is a procedure that comprises simultaneously denitrify ammonium as a hydrogen donor and nitrite as a hydrogen receptor by oxidizing bacteria of Anaerobic ammonium according to the following reaction formula:

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(Fórmula 1)1.0NH4 + 1.32NO2 + 0.066HCO3 + 0.13H + → 1.02N2 + 0.26NO3 + 0.066CH2O_ { 0.5} N 0.15 + 2.03H 2 O

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(Formula 1)

This procedure has advantages because the ammonium used as a hydrogen donor can reduce considerably the amount of methanol used for the denitrification and reduce the amount of a sludge produced, etc. Therefore, the procedure is considered to be a procedure effective to eliminate nitrogen in the future. The US document 2001/025814 A1 describes a procedure to collect cells bacterial using a membrane separation unit.

Summary of the Invention

However, it is difficult and takes a long time bind anaerobic ammonium oxidizing bacteria used for Anaerobic oxidation of ammonium to pills and acclimatize bacteria (They make bacteria proliferate), which is a major obstacle for the practical application of the procedure.

It is reported that the bacteria that carry out anaerobic ammonium oxidation are Planctomycete , although the details are not clear and the bacteria have a very low proliferation rate of 0.001 h -1 (Strous, M. et al., Nature, 400, 446 (1999)).

According to patent application publication Japanese No. 2003-24990, bacteria have a very small specific proliferation rate of 0.02 to 0.05 day -1 and lasts 14 to 35 days of cultivation to double the amount of  bacterial cells

To immobilize the oxidizing bacteria of anaerobic ammonium on pills is necessary to bind bacteria to an immobilization material and make bacteria proliferate First. However, because the proliferation rate is small as described above, even this binding stage It lasts a long time.

The current production equipment of a system of nitrogen removal using anaerobic ammonium oxidation It hasn't worked in Japan so far. Therefore, when the current production starts due to an activated sludge or similar it is necessary to start production after a long acclimatization period required or provide a plant crop manufactured by a plant manufacturer, etc. to grow Anaerobic ammonium oxidizing bacteria.

Due to the above circumstances, when the operation of a water treatment system begins residuals that uses anaerobic ammonium oxidizing bacteria, the system requires a long period of acclimatization that has not been had in acclimatization of wastewater treatment conventional.

In the system to be used practically not only one huge plant will be provided that requires very senior teams and performance management for the operation, but a large amount must also be controlled of nitrogen wastewater.

The present invention has been achieved in view of such circumstances. An object of the present invention is provide a procedure and an apparatus for collecting cells bacterial and wastewater treatment equipment that can effectively collect anaerobic ammonium oxidizing bacteria highly active water treated in an oxidation vessel anaerobic ammonia and thus not only be able to solve the problems previous but also improve oxidation performance anaerobic ammonia. This object has resulted in the procedure of claim 1 and the equipment as defined in the claim 3. Preferred embodiments are defined in the claims 2 and 4 and the following description.

According to the present invention, to achieve the object mentioned above a procedure is provided to collect bacterial cells comprising the steps of: feed the water to be treated that contains ammonium and nitrite to an anaerobic ammonium oxidation vessel to denitrify the ammonium and nitrite by ammonia oxidizing bacteria anaerobes; and feed the treated denitrified water to a acclimatization vessel provided on a path of a water pipe treated as feedback pipeline to anaerobic ammonium oxidation vessel to collect the anaerobic ammonium oxidizing bacteria in treated water as immobilized microorganisms attached to an immobilization material in the acclimatization vessel.

As a result of extensive studies, inventors of the present application have confirmed that the bacteria  anaerobic ammonium oxidants exist in the treated water obtained by treating the water to be treated containing ammonium and nitrite by anaerobic oxidation of ammonium, although the amount it is as small as several mg / l and the bacteria are extremely active.

Therefore, the oxidizing bacteria of Anaerobic ammonium in treated water can be collected as immobilized microorganisms attached to the immobilization material in the acclimatization vessel by feeding the water treated to an acclimatization vessel with a material of immobilization or recirculating water through the container of acclimatization to an anaerobic ammonium oxidation vessel. He time to acclimatize anaerobic ammonium oxidizing bacteria can be reduced considerably compared to the technique previous acclimatizing immobilized microorganisms collected.

According to the present invention, because the anaerobic ammonium oxidizing bacteria can acclimatize in a shortly, anaerobic oxidation of ammonia may present a improved performance and the device does not need to have a great size.

According to a preferred aspect of the present invention is provided the procedure to collect cells bacterial according to the above description in which the material of immobilization for immobilized microorganisms is one of pills and a fixed bed. Any pill or bed fixed assets can be used as immobilization material for immobilized microorganisms. When microorganisms fixed assets are introduced or placed in a container of anaerobic ammonium oxidation in which the acclimatization can prevent ammonium oxidizing bacteria anaerobes out of the anaerobic oxidation vessel of ammonium and also the acclimatization in the oxidation vessel anaerobic ammonia can be carried out in a longer term short.

In the present invention, bacteria Anaerobic ammonium oxidants are collected as microorganisms fixed assets attached to an immobilization material.

According to another aspect of the present invention, to achieve the aforementioned object a apparatus for collecting bacterial cells that is configured to carry out the procedure to collect bacterial cells according to the present invention.

The device has a configuration to apply the procedure for collecting bacterial cells of the present invention and thus be able to effectively collect oxidizing bacteria from extremely active anaerobic ammonia left in treated water by anaerobic oxidation of ammonium. Therefore, the period of acclimatization can be greatly reduced when bacteria collected anaerobic ammonium oxidizers are used for the acclimatization as inoculum.

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In addition, the water treatment equipment residuals comprising the apparatus for collecting cells bacteria of the present invention as part of the configuration can effectively collect anaerobic ammonium oxidizing bacteria highly active in treated water. The acclimatization period can be reduced considerably by starting a container of anaerobic ammonium oxidation that uses the oxidizing bacteria of collected anaerobic ammonium.

Brief description of the drawings

Fig. 1 is a conceptual view to describe the complete configuration of the water treatment equipment residuals by anaerobic oxidation comprising the apparatus to collect bacterial cells according to the present invention;

fig. 2 is a conceptual view to describe the complete configuration of the water treatment equipment residuals by anaerobic oxidation of ammonium comprising the apparatus for collecting bacterial cells according to one embodiment preferred of the present invention;

fig. 3 is a conceptual view to describe the complete configuration of the water treatment equipment residuals showing a modification of the first embodiment shown in fig. one.

Detailed description of the preferred embodiments

Preferred embodiments of the procedure and the apparatus for collecting bacterial cells, the procedure for acclimatize bacterial cells and water treatment equipment Residues of the present invention will be described below. through the attached drawings.

Fig. 1 is a conceptual view to describe the complete configuration of water treatment equipment 10 residuals by anaerobic oxidation of ammonium comprising the apparatus for collecting bacterial cells according to the present invention.

As shown in fig. 1, team 10 of wastewater treatment is configured by providing as main constituent an acclimatization vessel 14 for collect and acclimatize anaerobic water oxidizing bacteria ammonia below an anaerobic ammonium oxidation vessel 12. In this case, the apparatus for collecting bacterial cells is constituted by the acclimatization vessel 14.

The water to be treated containing ammonium and nitrite circulating in a pipe 20 of raw water is fed to the Anaerobic ammonium oxidation vessel 12 by a pump (not shown). The water treated in the oxidation vessel 12 Anaerobic ammonia is fed by a first pipe 22 to acclimatization container 14 and is discharged from container 14 of acclimatization by means of a pipe 24 of treated water to the outside of the system.

The water to be treated (raw water) that Contains ammonium and nitrite is circulated inside container 12 Anaerobic oxidation of ammonium and ammonium and nitrite contents in raw water they are simultaneously denitrified by anaerobic ammonium oxidizing bacteria in container 12 of anaerobic ammonium oxidation.

The acclimatization vessel 14 includes one of pads and an immobilized bed as immobilization material. When the treated water comes in contact with the material of immobilization, anaerobic ammonium oxidizing bacteria in the treated water bind to the immobilization material. This is how they form microorganisms immobilized with ammonia oxidizing bacteria bound and immobilized anaerobes on the material of immobilization Anaerobic ammonium oxidizing bacteria in the treated water is collected with immobilized microorganisms formed.

The acclimatization vessel 14 is preferably closed and preferably has a structure in or from which the immobilization material can move. For example, it is effective if the immobilization material is previously placed in a container with a unitary structure through which you can permeate the water and from which the material is prevented from leaving immobilization out, such as a box made of a cloth metallic or plastic cloth, and the container is dipped in or taken out of the acclimatization vessel 14. In addition, preferably install a pressure gauge upstream or downstream of the acclimatization vessel 14. This is because the operation of the Anaerobic ammonium oxidation vessel 12 stops when the acclimatization vessel 14 crashes, but such a problem can be avoided if upstream or upstream pressure can be detected below the acclimatization vessel 14. The vessel 14 of acclimatization does not necessarily have to be configured as a "container" and can be incorporated into the water pipe 22 treated.

As described above, such bacteria anaerobic ammonium oxidants have a very high proliferation rate low. However, thereby providing the container 14 of acclimatization downstream of the anaerobic oxidation vessel 12 of ammonia, anaerobic ammonium oxidizing bacteria extremely active in the treated water of the anaerobic oxidation vessel 12 of ammonium can be collected as immobilized microorganisms and acclimatize in the acclimatization vessel 14. In addition, the collected anaerobic active ammonium oxidizing bacteria can acclimatize in another acclimatization vessel or can be introduced or placed in an anaerobic ammonium oxidation vessel that It will get going and acclimatize. Therefore, the period of acclimatization can be greatly reduced compared to acclimatization of a usual activated sludge.

Examples of material for tablets such as immobilization material include, but are not limited specifically a, polyvinyl alcohol gels, acid alginic and polyethylene glycol; and plastic cellulose tablets, Polyester, polypropylene and vinyl chloride. The pills are they preferably form in the form of a sphere, a cylinder, a porous material, a bucket, a sponge, a honeycomb or Similar.

In addition, granules can be used using the autogranulation of microbes.

Examples of material for a fixed bed as immobilization material include, but are not limited to specifically a, polyethylene, polyester, plastic materials polypropylene and vinyl chloride; and active carbon fibers. Examples of the shape of an immobilized bed include, but are not specifically limited to, a form formed in a fiber, a Chrysanthemum or a honeycomb. In addition, an immobilized bed can  be formed by filling a basket or similar with immobilized microbes on the tablets described above or microbes immobilized on the granules.

According to the apparatus 10 to collect cells Bacterial with such a configuration, treated water denitrified is fed to the acclimatization vessel 14 and the anaerobic ammonium oxidizing bacteria bind and immobilize on the immobilization material in the container 14 of acclimatization. Because the ammonium oxidizing bacteria anaerobes are in a small amount, but they are extremely active, anaerobic ammonium oxidizing bacteria can only join the immobilization material by submerging the material of immobilization in the treated water in the container 14 of acclimatization. Therefore, the time to acclimatize the bacteria anaerobic ammonium oxidizers can be greatly reduced in comparison with the prior art.

Fig. 2 is a conceptual view to describe the complete configuration of the water treatment equipment 100 residuals by anaerobic oxidation of ammonium comprising the apparatus for collecting bacterial cells according to one embodiment Preferred of the present invention. In this case, the device for collecting bacterial cells consists of a container of acclimatization and a precipitation vessel. The same device or element in fig. 1 will be described with the same number of reference and repeating the same description is omitted.

The present embodiment differs from the first embodiment in fig. 1 in which the embodiment has a configuration in which a precipitation vessel 16 is installs downstream of an anaerobic oxidation vessel 12 of ammonium, and an acclimatization vessel 14 or a container of acclimatization is installed on top of container 16 of precipitation. Therefore, among the ammonium oxidizing bacteria anaerobes in treated water, ammonia oxidizing bacteria anaerobes that float in the treated water bind to a material of immobilization in the acclimatization vessel 14 and are collected as immobilized microorganisms as in the first embodiment. In addition, anaerobic ammonium oxidizing bacteria in a mud that they go out in the company of the treated water they precipitate and are collected like a mud of bacterial cells. Therefore, all bacteria Anaerobic ammonium oxidizers in the treated water can be collected effectively. The bacterial cell sludge precipitated in the precipitation vessel 16 can be fed again by a second pipe 26 to the anaerobic oxidation vessel 12 of ammonium or can be discharged through a discharge pipe 32 mud outside the system. The bacterial cell sludge downloaded to the outside of the system can be introduced to another acclimatization vessel or other oxidation vessel 12 anaerobic ammonia to get going and acclimatize as a inoculum Alternatively, the sludge can bind directly to e immobilize on immobilization material or get caught and immobilize in an immobilization material to form immobilized microorganisms and introduce microorganisms immobilized in another acclimatization vessel or container of anaerobic ammonium oxidation. If a separation unit is used of membrane (not shown) instead of container 16 of precipitation, the unit can act and present the effect on the the same way.

Fig. 3 shows the 200 treatment equipment of wastewater showing a modification of the embodiment shown in fig. 1 in which an acclimatization vessel 14 is provides in a recirculation line that makes a part or all water treated in an anaerobic oxidation vessel 12 of ammonium circulate back to the entrance of the container 12 of anaerobic ammonium oxidation. The same device or element as in fig. 1 will be described with the same reference number and omitted the repetition of the same description.

Specifically, part or all of the water treated in the anaerobic ammonium oxidation vessel 12 is feeds through a second pipe 26 as a pipe feedback to the acclimatization vessel 14 and the second water treated in the acclimatization vessel 14 is recirculated by a third pipe 30 as a feedback pipe to the container 12 anaerobic oxidation of ammonium. In the second pipe 26, provides a recirculation pump 28 as a piping feedback.

Therefore, anaerobic ammonium oxidizing bacteria can only bind to the immobilization material by immersing an immobilization material, such as tablets, granules or an immobilized bed that can immobilize anaerobic ammonia oxidizing bacteria on it, in the recirculation water (container 14 acclimatization). Accordingly, anaerobic ammonium oxidizing bacteria can be efficiently collected and immobilized microorganisms in which anaerobic ammonium oxidizing bacteria are attached to the immobilization material in the acclimatization vessel 14 can be effectively acclimatized. The anaerobic ammonium oxidizing bacteria collected in the acclimatization vessel 14 can be acclimatized in a separate prepared acclimatization vessel or can be acclimatized in an anaerobic ammonium oxidation vessel to be started. Therefore, the period
Acclimatization can be greatly reduced compared to the acclimatization of a usual activated sludge.

Examples

Examples of the following will be described present invention However, the present invention should not Limit yourself to these examples.

Example 1

An acclimatization test of anaerobic ammonium oxidizing bacteria using the 10 kit of wastewater treatment of anaerobic ammonium oxidation shown in fig. one.

Residual water tested

As wastewater tested, water was used. inorganic synthesized residual.

A raw water composition used a composition shown in table 1 with reference to A.A. they go from Graaf et al., Microbiology (1996), 142, p. 2187-2196. The operation was carried out changing the nitrite nitrogen concentration (NO2 -N) and nitrogen concentration ammoniacal (NE4 -N).

TABLE 1

one

Treatment conditions

The operation was carried out at a water temperature of 36 ° C, at a HRT of 3 hours and at a rate of denitrification of 2.8 to 3.2 kg-N / m 3 / day. The SS concentration in the treated water at this time was 0.2 to 2.0 mg / l In an acclimatization vessel 14 in fig. 1A se placed a non-woven support of biomass as a material of immobilization After immersing it for about 3 weeks, the non-woven biomass support was removed and subjected to Next continuous flow test.

The wastewater was adjusted to have a NH4 -N concentration of 35 mg / l and a NO2 -N concentration of 35 mg / l with reference to table 1 and acclimatization was carried out to a HRT 6 hours to gradually increase the nitrogen concentration in the raw water. As a result, the rate of denitrification reached 2.8 kg-N / m 3 / day on day 42 after of starting the operation. Therefore, it was confirmed that the Acclimatization was satisfactory.

Comparative example one

A test was conducted under them operating conditions as in example 1, except that used a completely new non-woven biomass support.

The acclimatization vessel was filled with a completely new non-woven biomass support and at the same added a sludge of anaerobic ammonia oxidizing bacteria. Like in Example 1 (volume in the container: 300 mg / l, based on a total volume), the wastewater was adjusted to have a NH4 -N concentration of 35 mg / l and a NO2 -N concentration of 35 mg / l and the Acclimatization was carried out at a HRT of 6 hours. After 60 days it was confirmed that the acclimatization vessel was put finally underway.

It is known that a mud of oxidizing bacteria from Anaerobic ammonium can become a sedimentary floc. In addition, because bacterial cells other than bacteria disperse and wash, it is difficult to make cells join a nonwoven support of biomass in a container.

Specifically, the procedure to collect Bacterial cells of the present invention is to form a inoculum for commissioning. Not the whole procedure of Acclimatization is carried out using the inoculum. However due that anaerobic ammonium oxidizing bacteria only proliferate With difficulty, it is difficult to form an inoculum of the bacteria. By therefore, it can be assumed that the acclimatization period can be reduced considerably by starting a container of anaerobic ammonium oxidation using the inoculum formed by the procedure to collect bacterial cells of the present invention.

Example 2

An acclimatization test of anaerobic ammonium oxidizing bacteria using 200 equipment anaerobic ammonia oxidation wastewater treatment shown in fig. 3. After dipping the granules in methane, with which an acclimatization vessel 14 was filled, the test was carried out in recirculation water for approximately 10 days, using a UASB reactor (anaerobic flow mud mantle upward).

A container 12 for anaerobic oxidation of ammonium as a source of recirculation lines 26 and 30 worked under the same conditions as in example 1 at a temperature of water of 36ºC, at a HRT of 3 hours and at a rate of denitrification from 2.8 to 3.2 kg-N / m 3 / day.

In the same way as in example 1, water residual was adjusted to have a concentration of NH4 -N of 35 mg / l and a concentration of NO2 -N of 35 mg / l and acclimatization was brought to conducted at a HRT of 6 hours to gradually increase the Nitrogen concentration in raw water. As a result, the rate of denitrification reached 2.1 kg-N / m3 / day in on day 38 after starting operation. Therefore, it confirmed that acclimatization was satisfactory.

Claims (4)

1. A procedure to collect cells Bacterial comprising the stages of: feed the water to be treated that contains ammonium and nitrite to an anaerobic ammonium oxidation vessel (12) to denitrify ammonium and nitrite by bacteria anaerobic ammonium oxidants; Y feed the treated denitrified water to a acclimatization vessel (14) provided in a trajectory of a treated water pipe or a feedback pipe to Anaerobic ammonium oxidation vessel (12) to collect the anaerobic ammonium oxidizing bacteria in treated water as immobilized microorganisms bound to a material of immobilization in the acclimatization vessel (14). 2. The procedure to collect cells bacteria according to claim 1, wherein the material of immobilization for immobilized microorganisms is one of pills and a fixed bed. 3. Equipment for treating wastewater that understands: an anaerobic ammonium oxidation vessel (12) to denitrify a water to be treated that contains ammonium and nitrite by anaerobic oxidation bacteria of ammonium; a precipitation vessel that provides after anaerobic ammonium oxidation vessel (12), the precipitation vessel to collect and precipitate the Anaerobic ammonium oxidation bacteria contained in water treated fed from the anaerobic ammonium oxidation vessel (12); Y one of pills or an immobilized bed provided in the precipitation vessel to join the Anaerobic ammonium oxidation bacteria in treated water at same. 4. The equipment according to claim 3, which It also includes a recirculation line to recirculate water treated from the precipitation vessel to the oxidation vessel anaerobic ammonia (12).